1/2 cup unsalted butter, melted and cooled slightly
1 cup light brown sugar, packed
dash of salt
1 1/2 tablespoons vanilla extract
3/4 cup all-purpose flour
2 cups graham crackers, roughly chopped
1 1/4 cup mini marshmallows
1 cup semi-sweet or milk chocolate chips
Preheat oven to 350 degrees F.
Line an 8-by-8-inch baking pan with parchment paper leaving enough for overhang. Lightly grease and set aside.
In a large mixing bowl add the cooled melted butter, egg, brown sugar, salt, and vanilla, whisk until smooth.
Mix in the flour and stir until just combined. Add the graham crackers and stir well. Using a large rubber spatula, gently fold in the marshmallows and chocolate chips. Do not over-mix.
Pour the batter into the prepared baking pan, use a spatula to smooth out slightly.
Place in the oven and bake until the top is slightly golden and set, about 25 minutes. Allow bars to cool in pan for at least 20 minutes before slicing.